01Real structures
Structures, not sketches.
PSMA turns at the centre while ten real ligands of ten modalities — a Fab, a nanobody, peptides, aptamers — orbit it.
PyMOL render of PDB 4NGM and ten deposited ligand structures; not AI-generated.
OpenEPI
Open tools. Open models.Science for everyone.
Epitorix builds for science and infrastructure first: the tools are open today, and earlier versions of the EPiQ™ models will be released here so the same instruments reach every lab.
Free, no sign-in needed for the tools.
Three commitments
01Available now
Open tools
Browser tools for radiopharmaceutical work, free to use and to link to, with every number carrying its source.
02Coming soon
Open models
Earlier EPiQ model versions, released with documentation for reproducible science.
03Announced here and in News
Competitions
Grant prizes for open problems in radiopharmaceutical design; details are posted here and announced in News.
The tools
Seven instruments, open in the browser.
No account, no install. Sign in only if you want to keep your work.
All 7 open now
01Calculator
Open now
Kd to pKd and ΔG
Convert a dissociation constant to pKd and binding free energy at any temperature, with the formulas and worked examples.
Open
02Calculator
Open now
Decay and activity planner
Activity at injection from a calibration, or the reverse, for 27 clinical radionuclides or any half-life, with the decay curve and unit conversions.
Open
03Calculator
Open now
Molar and specific activity
GBq/µmol, Ci/µmol and GBq/mg from an activity and an amount, against the carrier-free maximum for the nuclide.
Open
04Calculator
Open now
SUV calculator
Standardized uptake value from a tissue concentration, the injected activity decay-corrected to scan time, and body weight, lean mass or surface area.
Open
05Analyzer
Open now
Peptide analyzer
Mass, pI, charge against pH, hydropathy, aromaticity, extinction coefficient and composition from a one-letter sequence.
Open
063D viewer
Open now
Structure viewer
Any PDB entry or your own file, rendered in the browser: cartoon, surface, sticks, chain and B-factor colors, distances, PNG export.
Open
07Reference table
Open now
Isotope half-lives
27 therapeutic and diagnostic radionuclides: half-life, decay mode, principal emissions and clinical use, each cited.
Open
Reference tools, not Epitorix performance. Every model figure on this page is quoted from Science with its own fence and links back to the beat that owns it; nothing here adds a claim of its own — numbers, methods and program status live on Science and Pipeline.
All toolsWhat's inside
What Epitorix is opening up.
Six frames from the work behind OpenEPI: real structures, the ranking picture, the anatomy chapter, the proteome scan and the open instruments.
02Ranking
Ranking by predicted pKd.
Give Xenoclea 100 generated ligands and, in internal benchmarks, it recovers more than 80% of your true top ligands.
Internal benchmarks; a preprint describing the evaluation is forthcoming.
Your ligandsSmall moleculesPeptidesNon-canonical peptidesMacrocyclesAntibodiesNanobodiesMini-proteinsDNA/RNA ligandsEpitorixRanked- 01
- 02
- 03
- 04
- 05
…
Predicted pKd · illustrative
03Biodistribution
Biodistribution before trials.
Biodistribution, organ and cell-type risk, PK and PD — predicted before a trial reveals them.
Schematic of physiological FDG distribution; not patient data.
Brain: SUVmean 6.8 ± 1.0; Heart: SUVmean 3.8 ± 2.4 · 4 h fast; Liver: SUVmean 2.3 ± 0.3; Kidneys: SUVmean 2.9 L · 3.2 R; Bladder: SUVmean 35.4 · excreted tracer. after Gutschmayer et al., Sci Data 2025. 04Off-target prediction
Off-target binding, proteome-wide.
Epitorix screens binders, peptides and small molecules against the whole proteome computationally, in about an hour.
>90% recall on known off-target interactions, in retrospective analyses
- NCAM1
- SSTR1
- CXCR4
- ATRNL1
- PRKG1
- BCL2
- FXYD2
- PLPP1
05Open tools
Seven tools, no account.
Kd and pKd, decay, molar activity, SUV, peptide properties, structures and isotope half-lives — computed in the browser, sources beside each result.
Reference tools, not Epitorix performance.
06Structure viewer
A real complex, in motion.
The HER2 extracellular domain with the trastuzumab Fab, PDB 1N8Z — the structure the viewer opens with, rendered from deposited coordinates.
PDB 1N8Z, rendered from deposited coordinates; not AI-generated.
Six assets the site already ships; every number is quoted from Science with its fence.
Competitions
Grant prizes for open problems.
We have grant prizes for competitions: open problems in radiopharmaceutical design, posted on this page and announced in News when they open.
- 01Problem 01to be announced
- 02Problem 02to be announced
- 03Problem 03to be announced
Entries open with an announcement in News. Until then the board holds its places.
Notify meHow competitions work
- 01AnnounceThe problem, its grant prize and its rules are posted here and in News.
- 02SubmitEntries are made from a free Epitorix account.
- 03AwardThe grant prize is awarded and the result is announced in News.
No dates are promised; each competition opens with its announcement.
Laboratory bench · liquid handler and assay plates
Why open
Science moves faster when the same instruments reach every lab.
Epitorix cares more about the science, the infrastructure and the models than about keeping them behind a door. OpenEPI is where that shows: the tools we build for our own work are open to use and to link to, and as the EPiQ models move on, their earlier versions will be released here with the documentation needed to reproduce a result.
Competitions with grant prizes will put open problems in radiopharmaceutical design in front of anyone who wants to work on them. Details are posted on this page and announced in News.
Roadmap
No dates are promised. Each station is announced on this page and in News when it is ready.
- 01Tools openNow
- 02Models open-sourcingComing soon
- 03CompetitionsAnnounced here
Accounts and contact
Keep your work. Hear first.
A free account saves your results, enters you in competitions when they open, and gives early access to the open models. For anything else, write to us.